Hello everyone;
I apologize if this problem has been discussed already but I am really a beginner and my problem has persisted for a long time:
My database is oracle 10g I created (the database was really created by default during installation) a base whose SID is "orcl". She is on a remote database server data (Windows). I checked the file tnsnames. ora file listener.ora file sql.ora but the connection does not work with oracle sql I develop on my machine oracle client is installed. is there any recommendations to check a file changes ...
Thank you it is very urgent

ok my friend You Have Reason. I described the condition: I work with a pc in which Oracle client(10g) is installed, operating system windows xp sp2 . the oracle server is installed on a server remote database with the operating system is Windows Server 2008. this server belongs to a domain. I try to connect to the Oracle database located on the server. For this I made 2 methods:
1 - I try to connect to oracle using oracle sql developer but even by providing the connection parameters login password username, SID,IP there is an error message: "Exception I / O: the network adapter could not establish the connection "
2-I tried to get connected through a vb.net application that I used to connect to a local oracle database here is the error message: "ORA-12170:
TNS: Connect timeout occurred "

Here is my problem. is that there's other information I have provided?
Note well: I tried to connect from a PC in the same domain and another not belonging but the same problem.
Thank you.